ENERGY-DEPENDENCE OF THE HE-4(PI(-)) TOTAL CROSS-SECTION(),PI()

The total cross section of the He-4(pi(+), pi(-)) reaction was measure d for pi(+) kinetic energies ranging from 70 to 130 MeV using the CHAO S spectrometer at TRIUMF and a liquid 4He target. Around T-pi=90 MeV, total cross sections exceed conventional model predictions by a factor of 3, whereas at T-pi=70 MeV and for T-pi >130 MeV the data are consi stent with these calculations. An attempt is made to understand this b ehavior by assuming the production of the hypothetical d' dibaryon.